Codebook restriction and sub-sampling for channel state information reporting

A method for wireless communication at a base station, comprising:

• transmitting, to a user equipment (UE), an indication of a plurality of codebook sets, each codebook set including one or more precoding matrices for precoding downlink transmissions to the UE;
• indicating, to the UE, at least one set of the plurality of codebook sets for the UE to evaluate to determine one or more preferred precoding matrices;
• and
• receiving, from the UE, a precoding matrix indicator (PMI) of the one or more preferred precoding matrices in a channel state information (C SI) report.

A mobile device for wireless communication, comprising:

• a processor;
• memory in electronic communication with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the mobile device to:
• receive, from a base station, an indication of a plurality of codebook sets, each codebook set including one or more precoding matrices for precoding downlink transmissions to the mobile device;
• identify at least one set of the plurality of codebook sets to be evaluated for determining one or more preferred precoding matrices;
• evaluate the one or more precoding matrices in the at least one set to determine the one or more preferred precoding matrices;
• and
• transmit, to the base station, a precoding matrix indicator (PMI) of the one or more preferred precoding matrices in a channel state information (C SI) report.

A network device for wireless communication, comprising:

• a processor;
• memory in electronic communication with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the network device to:
• transmit, to a user equipment (UE), an indication of a plurality of codebook sets, each codebook set including one or more precoding matrices for precoding downlink transmissions to the UE;
• indicate, to the UE, at least one set of the plurality of codebook sets for the UE to evaluate to determine one or more preferred precoding matrices;
• and
• receive, from the UE, a precoding matrix indicator (PMI) of the one or more preferred precoding matrices in a channel state information (CSI) report.